Histopathology

Question 1

What is a tumour?

Answer 1

swelling of part of body caused by abnormal growth of tissue ; Benign or Malignant

Question 2

Histology definition

Answer 2

study microscopic structures of tissues

Question 3

Histopathology definition

Answer 3

study of microscopic anatomical changes in diseased tissues

Question 4

Cytopathology definition

Answer 4

Examination of cells to Identify signs + characteristics or disease

Question 5

Sample Prep Steps (3)

Answer 5

Fixation, Embedding + Sectioning

Question 6

FNAC

Answer 6

Fine needle aspiration Cytology extracts cells from lumps / diseased areas

Question 7

Cytology processing

Answer 7

smeared on side, Stained + examined by microscopy

Question 8

Fixation by Dehydration

Answer 8

Immersion in increasing alcohol concs allows gradual hydrophobicity changes

Question 9

Paraffin embedding process

Answer 9

Heat paraffin to 60 °C + allow to harden overnight

Question 10

Paraffin Sectioning Process

Answer 10

Microtome cuts into small slices + sections dried onto slide

Question 11

Paraffin embedding Pros + cons (1 of each)

Answer 11

long term preservation
damage biological functionality

Question 12

Frozen tissue fixation

Answer 12

immersion in Liquid Nitrogen or solvent

Question 13

Frozen embedding

Answer 13

Mounted in OCT Embedding medium + frozen at -80 °C

Question 14

Frozen Sectioning

Answer 14

Cut on cryostat

Question 15

Frozen tissue pros + cons

Answer 15

Retain enzymatic activities + quicker
Thicker sections = lower resolution + No long term preservation

Question 16

What H+ E staining shows + colours

Answer 16

structural info
Nuclei = blue
cytoplasm= pink

Question 17

Differential staining

Answer 17

Divides microorganisms into groups based on staining properties e.g Gram s town

Question 18

specialised stains

Answer 18

Disease diagnosis by staining special cell types/ components e.g PAS

Question 19

Immunohistochemistry (IHC) detects

Answer 19

Detect presence of critical marker proteins e.g cancer diagnosis

Question 20

In Situ Hybridization detects

Answer 20

Detects target RNA+ DNA using probes + fluorescence (FISH) or chromogenic dyes (CISH)

Question 21

What is Direct IHC + shows?

Answer 21

primary Ab binds target protein with fluorescent tag or enzyme + shows presence + location

Question 22

Ab - Ag visualization techniques

Answer 22

Tagged fluorophone = fluorescence
conjugated Ab-enzyme = colour change

Question 23

How IHC is used in cancer diagnosis

Answer 23

use specific tumour markers to determine if benign or malignant , stage / grade + origin of metastates